Pneumatic motor for lubricant pumps



NOV. 10, 1936. E w, DAVls 2,060,180

FNEUMATIC MOTOR FOR LUBRICANT PUMPS Filed May 15, 1952 2 Sheets-Sheebl@j 7g l lq J2 .Nov 10, 1936. E. w. DAvls 2,060,180

PNEUMATIC MOTOR FORv LUBRICANT PUMPS Filed May 16, 1932 2 Sheets-Sheet 2Patented Nov. l0, l1%.)36

aalst i ATENT oFFica PNEUMATICI Moron vFoil Lnmncm Puurs' Ernest w.Davis, oakrark, m., um. by meme assignments, to Stewart-WarnerCorporation,

Chicago, Ill., a corporation of Vlrllnia Application my 16.1933, seraiNo. 11,495

My invention`relates generally to lubricating apparatus and moreparticularly. to lubricant pumps and pneumatic motor means foroperating' the same. l l

It is an object of my invention to provide an 'improved pneumatic motorfor operating a reciprocating pump which is of simpliiied constructionand which may be economically manufactured.

It is a further object of my invention to provide an improved lubricantpump of the type usable to withdraw grease from barrels lor othercontainers. i

It is a further object of my invention to provide an improved valveoperating mechanism for reciprocating pneumatic motors.

Other objects will'appear from thefollowing description, reference beinghad to the accompanying drawings, in which Figure 1 is an elevation ofthe pump of my invention, illustrating its use in emptying a barrel; y

Figure 2 is a central vertical sectional view of the pump;

Figure 3 is an enlarged central vertical sectional view of the air valvemechanism;

Figure 4 is a transverse sectional view taken on the line iii-ll of Fig.2; and

Figure 5 is a fragmentary view of the valve housing.

The invention is illustrated as embodied in a pump used for dischargingthe contents of abarrel or other container, although it may be embodiedin any desired type of lubricant pump. The pump comprises a tubularcylinder l0, the

upper end of which is threaded in a casting i2 forming the upper head ofthe pump cylinder. A foot valve seat l@ is threaded in the lower end ofthe cylinder l@ and has crescent shaped inlet ports it which arenormally closed by a thin sheet metal valve I8. The valve I8 is heldadjacent its seat by a pin 20 which is guided for limited verticalreciprocatory movement in the valve seat |55.

A piston 22 is secured to the lower end of a piston rod 24, being heldagainst a. shoulder 26 thereof by a nut 28. The piston 22 has inletports @El which are shaped similar to the inlet ports I6. AA valve 32normally covers the ports 30. This valve is guided on the reduced endportion 34 of the piston rod 24. The piston rod 24 is threaded in thelower end of a hollow piston stem 36,

being secured against accidental unscrewing therefrom by a cotter pin38. The piston stem 36 is guided by a washer 40, a pair of flexibleleather t claim. (c1. rc1-+164) gaskets 42, 44 being provided to form apacking between the washer-and the stem. The leather Vgaskets ,and thewasher 40 are held in place by a bushing 46 threaded in the head 2. Thewasher is provided with one or more diametral holes 5 4I vand anlannular groove 48, which when the washer is in position communicatewith an aperture 45. Any Ilubricant leaking past the gasket 44 ,willthus be vented to the atmosphere and not seep into the air cylinder tointerfere with the 10 operation of the air motor, and similarly any airleaking past the gasket 42 will be vented to the atmosphere and not leakinto the lubricant chamber to mix with the lubricant being pumped.

A double cup leather piston 48 is secured to 15 the upper end of thestem 36 by means of a tubular bushing 50 and is operable in the aircylinder formed by a tube 5-2. This tube is clamped between the head I2and a. valve body 54 by suittable tie rods 56, gaskets 58 forming anair-tight 20 seal between the ends of the tube and the head I2 and thevalve body 54 respectively. A nipple 60 is providedfor making adetachable connection with a compressed air supply hose 62. Thecompressed air supply hose is at all times in com- 25 munication withthe lower end of the cylinder 52 through a port 64. A pipe 66 conductscompressed air from said nipple to the central threaded bore 50 of thevalve body, the pipe being secured to both the valve body and to thehead I2 30 by any suitable air-tight coupling means such as thecompression couplings 10 shown in Figure 2.

The valve body 54 has a counterbore l2, the upper end of whichis closedby an apertured cap ifi which serves to hold a deformable lvalve seat itagainst the upper end of the valve body 54. A. disc valve 'iti is seuredto the upper reduced diameter end portion-00 of a valve stem 82, beingclamped thereon between a poppet valve 84 and a lock Washer 86 which isheld in place by a, nut 40 38 threaded upon the extremity of the upperend portion of the valve stem. Said portion of the valve stem'has aplurality of flutes 90, the shoulders formed by the spaces between theflutes forming a shoulder against which the valve 84 45 is clamped. Aseat 92 for the valve 84 is provided in a valve seat bushing 96 threadedin the bore 68, the latter serving also as an abutment for the upper endof a compression coil spring 98, the lower end of which rests upon ashoulder |00 50' on the valve stem 82. A hat washer gasket |02 preventsleakage of air around the valve stem 80. being clamped against ashoulder I 04 formed in the valve-body bya packing nut |06. A passageway|08 connects the counterbore l2 with the 55 upper end ofthe cylinderformed by the tube 62. As shown in Figure 5, the valve seat bushing 98is held in place by a hollow head set screw ||0 which presses a softmetal disc ||2 against the threads of the bushing.

A collar ||4 is riveted to the lower end of the valve stem 82 and formsa seat for the lower end of a compression coil spring I I8, the upperend of which abuts against the lower end of the sleeve 50.

A lubricant discharge conduit ||8 is secured to the head i2 by means ofa threaded bushing |20. A valved discharge nozzle |22 may be provided atthe extremity of the conduit ||8, if desired, to control the flowtherethrough.

In operation the tubular pump cylinder I0 is inserted in a barrel |24 orother suitable container, the lubricant contents ofwhich are to bewithdrawn, such barrel being customarily provided with a threadedopening |28. The pump cylinder |0 is of course preferably madesufficiently long so that the foot valve seat |4 will rest upon thebottom of the drum. .The air hose 62 is then connected to the nipple 60and the `va1ve nozzle |22 opened to permit discharge of lubricant. Uponconnection to the source of air under pressure with the parts in theposition shown in Fig. 2, the piston 48, together with its stem 36 androd 24 and lubricant piston 22, will be forced upwardly due to thepressure of the air on the lower surface of the double cup leatherpiston 48. The upper end of the cylinder 52 is at atmospheric pressuredue to the communication established by the passageway |08. During theupward stroke of the piston 22 the valve 82 will of course be closed bygravity and by the differential pressures on the opposite sides thereof,and any lubricant above the piston will be forced outwardly through thedischarge conduit ||8. During this upward movement of the piston 22 thevalve I8 will be raised and a new charge of lubricant sucked in from thebarrel through the inlet ports I6, past the valve |8.

During this upward movement of the piston 48 and its associated parts,the valve stem 82 will remain stationary due to the fact that theeffective area of the stem 82 is slightly greater than the area of thevalve 84 exposed to air pressure, and because this action of the airpressure is reinforced by the compression spring 88. When, however, thepiston 48 reaches the upper limit of its stroke, the lower end of thevalve stem 82 will be engaged by the bottom of the bore 31 formed in thestem 36, and the valve stem 82 and all parts connected therewith movedupwardly. This upward movement of the valve stem causes unseating of thevalve 84 and substantially simultaneous seating of the valve 18 againstits rubber composition seat 16.

As soon as the valve 84 is moved a minute distance from its seat 82, thelower surface of the valve 84 and the'lower surface of the disc valve 18will be subjected to the pressure of the compressed air, and the valvestem 82 will therefore be moved very rapidly upwardly until, as stated,the disc valve 18 firmly seats against its seat 16. The parts will thusassume the position in which they are shown in Figure 3. When in thisposition the compressed air will flow from the pipe 66 into the threadedbore 68 through the flutes 80 in the upper portion of the valve stem andinto the conterbore 12, from 'whence the air will flow through thepassageway |08 to the upper end of the cylinder 52. The eective area ofthe upper surface of the piston 48 is substantially that of the crosssectional area of the tubular cylinder 82, while the effective area ofthe lower surface is greatly reduced because of the piston stem 38. Thetotal pressure upon the upper surface of the piston will therefore bemuch greater than that exerted upon the lower surface thereof eventhough the unit pressure is substantially the same. This difference intotal pressure upon the opposite sides of the piston 48 will causedownward movement of the latter. During this downward movement, the footvalve il will of course remain closed, and the lubricant containedbetween this valve and the piston 22 will be forced through the portsinto the space above the piston 22. A certain proportion of thelubricant within the cylinder i0 will be ejected because of thedisplacement of the stem 86.

As the piston 48 reaches the lower limit of its stroke, its `sleeve 50will engage'the upper end of the spring |I6 and compress the `latteruntil the force exerted downwardly upon the valve stem 82 by the springis suillcient to overcome the force of the compressed air, which tendsto maintainthe valve stem 82 in its uppermost position. When 'thisoccurs, the valve stem 82 will have a quick snap action since as soon asthe seal between the disc valve 18 and its seat is broken, the pressureupon the opposite sides of the disc valve will be approximatelyequalized, and as a consequence the effective force of the compressedair tending to hold the valve stem 82 in its upper position, will begreatly and suddenly reduced. When the valve stem 82 is thus snapped toits lower position, the upper end of the cylinder 52 Will again be incommunication with the atmosphere and the above described cycle ofoperations repeated. The lubricant pump will thus continue operationuntil the supply of compressed air is shut off or until the valve in thenozzle |22 is closed and sufiicient back pressure built up in theconduit to stall the compressed air pump.

While the invention has been disclosed as applied to a low pressurelubricant dispenser, it is contemplated that it be employed for highpressure lubricant pumps by suitable modification of the lubricantcylinder and piston, and by the provision of suitable means for primingthe lubricant cylinder where such priming is necessary.

While I have illustrated and described a preferrecl embodiment of myinvention, many modications may be made without departing from thespirit of the invention, and I do not wish to be limited to the precisedetails set forth but desire to avail mystelf of all changes within thescope of the appended claims.

I claim:

1. In a lubricant pumping mechanism having a lubricant cylinder and apiston reciprocable therein; an air motor comprising, an air pistonoperatively associated with said lubricant piston, a cylinder for saidair piston, means for continuously supplying air under pressure to oneend of said cylinder, an quick snap-over poppet valve mechanism operableby said piston alternately to connect the other end of said air cylindert0 the atmosphere and to said source of air under pressure.

2. A fluid motor for the operation of .lubricant compressors comprisinga cylinder, a piston reciprocable therein, said piston having a stem ofappreciable cross sectional area projecting from A y 9,060,180 'tweensaid piston and said valve stemfa pair o! poppet type valves secured tosaid stem,A seats for said valves respectively, and passagewaysconnecting the other end of said cylinder with the atmosphere and withsaid vsource of air under pressure respectively, said passageways beingarranged to be closed alternately by said valves.

3. In a lubricant pumping mechanism having a lubricant; cylinder with areciprocable plunger; a pressure fluid motor providing the energy lorreciprocating :said' plunger to effeotthe discharge of lubricant fromsaid cylinder, said motor being operative to start from any position ofrest and comprising an air cylinder, a piston, a piston rod securedthereto and connected to said plunger, a source of pressure fluid, acontinuously open pneumatic connection between said source and one endof said air cylinder,'and a snapover valve mechanism operable by saidpiston alternately to connect the other end of said air cylinder tothe'atmosphere and to said source of pressure fluid.

4. In a iiuid ,motor foroperating a lubricant ypumping mechanism thecombination oi.' a cylinder and a piston, having a piston rod, with acylinder head, a pneumatic continuously open connection between thecylinder on the piston rod side of the piston and a source of pressureiluid, and means for intermittently supplying pressure iiuid to thecylinder on the opposite side of said piston comprising a valve chamberin said cylinder head, a passageway, including said chamber, forestablishing a pneumatic connection between said cylinder and a sourceof pressure uld,

Ipoppet valve means in said chamber, including a ,stern responsive to'movements of the piston for actuating said valve means, and springsassociated with said valve means to cause the latter to operate with asnap action.

5. -A fluid motor for operating lubricant pumping .mechanism comprisinga cylinder, a piston reciprocable therein, a piston'rod providing adriving connection for the pumping mechanism, a continuously openpneumatic connection be- .tween one end of said cylinder andthe sourceofI pressure iluid, a head for said cylinder including a valve chamber,passageways connecting said chamber with said cylinder. the atmosphere,and

said pneumatic connection, respectively and snap-acting poppet valvemeans in said chamber for controlling the passage of fluid through saidpassageways, and adapted alternately to connect the head end of saidcylinder with the atmosphere and with said pneumatic connection.

6.` In a iluid motor for operating a lubricant pumping mechanism, thecombination of a cylinder with a piston having a central bore andreciprocable in said cylinder, means for connecting one end of saidcylinder toa source o! fluid under pressure, a piston rod secured tosaid piston and having a bore coaxial with said piston bore, a head onthe other end of said' cylinder, a valve chamber in said head, a valvestem reciprocably secured in said head and projecting through saidcylinder into said bores, passageways connecting said chamber only withthe head end of the cylinder, the atmosphere, and a source of pressureuid respectively, poppet valve means in said chamber carried by saidvalve stem, and resilient means normally urging said ,valve stem andpoppet valve means toa position to close the passageways from the sourceof pressure iluid to the cylinder, -said piston rod being adapted toengage the vend of the valve stem near the completion oi.' the operativestroke of the piston to shift said poppet valve means to connect thehead end of ,the cylinder with the source of pressure fluid foreffecting the return of the piston.

7. A iluid motor -for operating lubricant pumping mechanism comprising acylinder, a piston reciprocable therein, a piston rod providing a powerconnection for the pumping mechanism, a pneumatic connection between oneend of said cylinder and a source of pressure iluld, said connectionbeing open at all times, a headv for said cylinder including a valvechamber, poppet valve means therein controlling the passage of fluid toI`and from the head end only of said cylinder, a

